Gossamer Bio Q1 2026 Earnings Report

Gossamer Bio EPS Results

• Actual EPS: -$0.20
• Consensus EPS: -$0.17
• Beat/Miss: Missed by -$0.03
• One Year Ago EPS: N/A

Gossamer Bio Revenue Results

• Actual Revenue: $16.96 million
• Expected Revenue: $4.67 million
• Beat/Miss: Beat by +$12.29 million
• YoY Revenue Growth: N/A

Gossamer Bio Announcement Details

• Quarter: Q1 2026
• Date: 5/15/2026
• Time: Before Market Opens
• Conference Call Date: Monday, May 18, 2026
• Conference Call Time: 8:00AM ET

Gossamer Bio (NASDAQ:GOSS) is a clinical-stage biopharmaceutical company headquartered in San Diego, California. Founded in 2012, the company is focused on discovering and developing oral, once-daily therapies for immune-mediated and inflammatory diseases, as well as oncology indications. Gossamer Bio leverages a deep pipeline of small-molecule candidates aimed at improving patient outcomes in areas of high unmet need.

The company’s lead programs include GB004, an S1P1 receptor modulator in late-stage development for ulcerative colitis, and GB1275, a CD11b modulator being investigated in solid tumors and hematologic malignancies. In addition to these clinical-stage assets, Gossamer Bio maintains several earlier-stage programs targeting pathways such as integrin and TGF-β signaling. The company’s R&D efforts are supported by a combination of in-house research capabilities and external collaborations with academic centers and contract research organizations.

Gossamer Bio completed its initial public offering in July 2019 and has since advanced multiple clinical trials across North America and selected international sites. The company is led by President and Chief Executive Officer Thomas A. Whiting, a veteran of the biopharmaceutical industry with over 25 years of drug development experience. Under his leadership, Gossamer Bio continues to build a multidisciplinary management team focused on accelerating the translation of scientific insights into therapeutic candidates.

Gossamer Bio Q1 2026 Earnings Call Transcript

Key Takeaways

• Positive Sentiment: Gossamer said its seralutinib Phase III PROSERA data showed a clinically meaningful improvement in six-minute walk distance, with all four key secondary endpoints favoring treatment, and management said the totality of the results supports a real treatment signal despite narrowly missing the prespecified alpha threshold.
• Positive Sentiment: The company advanced its FDA pathway to a Type B pre-NDA meeting in mid-June and reiterated a target NDA filing in September 2026, with potential approval still viewed for the third quarter of 2027 if the process goes as planned.
• Positive Sentiment: The PROSERA CT-FRI sub-study showed multi-compartment reverse remodeling, including improvements in arterial, venous, and fibrosis-like parenchymal measures, which management said provides mechanistic support for seralutinib’s effect in PAH.
• Neutral Sentiment: Management said the imaging findings are not a surrogate endpoint but could strengthen the NDA and potentially support a differentiated label, with the data expected to be included in the filing and discussed further with FDA.
• Negative Sentiment: Gossamer also disclosed aggressive cost actions, including a reduction in force affecting about half the company, reduced operating expenses, and a convertible note exchange that lowers debt from $200 million to $72 million while extending maturity to 2030.

Presentation

[Operator]

Thank you for standing by. My name is Tina, and I will be your conference operator today. At this time, I would like to welcome everyone to the Gossamer Bio Q1 2026 earnings call. All lines have been placed on mute to prevent any background noise. After the speaker's remarks, there will be a question-and-answer session. To ask a question, simply press star one on your telephone keypad. To withdraw your question, press star one again. It is now my pleasure to turn the call over to Bryan Giraudo, Chief Operating Officer and Chief Financial Officer. Please go ahead.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Good morning, and thank you for joining us. Before we begin, I'd like to remind listeners that today's discussion includes forward-looking statements, including statements regarding our regulatory plans, potential NDA submission and approval timing, commercialization expectations, cash runway, capital structure, and the potential therapeutic benefit in future developments of seralutinib. These statements are subject to risks and uncertainties that could cause actual results to differ materially.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Please refer to our SEC filings in today's press release for our discussions of these risks. We undertake no obligation to update these forward-looking statements except as required by law. We are very excited this morning to have on our call today, Faheem Hasnain, Caryn Peterson, Dr. Rob Roscigno. Additionally, we have Dr. Jean-Marie Bruey, Dr. Rainer Zimmermann, Dr. Megan Flynn, Dr. Richard Osterhout, and Bob Smith, our Chief Commercial Officer, to speak about our exciting results this morning.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Today, we plan to cover three topics. First, a regulatory update, including our Type B pre-NDA meeting. Secondly, we will discuss results from our PROSERA-CT-FRI sub-study. Third, an update on our capital structure, including the convertible note exchange. Our financial results for the first quarter of 2026 are included in this press release, I will come back to briefly discuss these at the end of the call. With that overview, let me hand it over to Faheem to discuss our recent progress. Faheem.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Yeah, thanks. Thanks, Bryan Giraudo, and good morning, everybody. In February, we reported top-line results from PROSERA, our phase III study of seralutinib in patients with PAH. At a high level, PROSERA showed a clinically meaningful placebo-adjusted improvement of 13.3 m in 6-minute walk distance at week 24, with patients on seralutinib improving 28.2 from baseline versus 13.5 m on placebo and a P value of 0.032. That P value met the traditional 0.05 threshold for statistical significance, it did not meet the pre-specified 0.025 alpha threshold.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

At the same time, all four key secondary endpoints favored seralutinib over placebo, we saw a stronger effect in the pre-specified risk-enriched subgroup. Taken together, we believe the totality of the PROSERA data supports a real and clinically meaningful treatment signal. Since the PROSERA top-line readout, we've been focused on three work streams in parallel. First, we engaged with the FDA on the path forward for seralutinib. That process advanced from the previously disclosed Type C meeting to a Type B pre-NDA meeting, which is the most formal pre-submission meeting type. The meeting has been confirmed as in-person, the briefing book has been submitted.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Caryn will cover that in more detail shortly. Second, we completed the analysis of the pre-specified CT-FRI sub-study, which enrolled 162 patients with 125 evaluable paired scans at week 24. Those results showed multi-compartment structural reverse remodeling across arterial, venous, fibrosis-like, and vascular complexity parameters. You will hear the full data shortly in the FRI section of the call. Third, we moved quickly on capital stewardship.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

We recognized immediately that while the top-line results was clinically meaningful, it also created uncertainty, and we needed to act decisively to protect the company's financial position and preserve our ability to get seralutinib to patients. That included a significant reduction in force, affecting approximately half the company, a sharp reduction in operating expenses as PROSERA winds down, and the pause of other development activities and broader cost containment across the organization.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

At the same time, we engaged constructively with our convertible noteholders to address the upcoming 2027 maturity. Bryan will cover the outcome of that process later in the call. All of these actions were taken for the same reason, to make sure this company has the runway, the focus, and the resources to pursue an NDA submission and ultimately get an approved treatment to patients with PAH. Our conviction in seralutinib has increased since the top-line readout, not decreased.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

That conviction is based on the totality of evidence, consistent drug arm performance in PROSERA, confirmatory data from TORREY, multi-compartment mechanistic evidence from the CT-FRI, and the regulatory path we're advancing with the FDA. This is a first-in-class inhaled tyrosine kinase inhibitor for a rare and fatal disease with high unmet need. We believe we owe it to patients to pursue this path with discipline and urgency. I'll turn it over to Caryn to discuss our regulatory interactions and next steps. Caryn.

[Caryn Peterson, EVP of Regulatory Affairs at Gossamer Bio]

Thanks, Faheem. Let me start with the regulatory pathway we are pursuing. We are pursuing an NDA submission under the framework of one adequate and well-controlled clinical investigation plus confirmatory evidence. This is consistent with FDA's recent guidance to articulate the flexibility in the amount and type of evidence needed to meet the substantial evidence standard in place since 1998. For Gossamer, that approach is supported by the totality of the phase III PROSERA dataset together with the phase II TORREY study.

[Caryn Peterson, EVP of Regulatory Affairs at Gossamer Bio]

We also believe the seriousness of PAH, the high unmet medical need, and seralutinib's novel mechanism of action, complementary to existing PAH therapies, all support this regulatory pathway. We plan to file the NDA based on the totality of the PROSERA and TORREY datasets, and any adjustments to patient population will be guided by regulatory feedback. Turning to our engagement with FDA, we are now moving forward with a Type B pre-NDA meeting rather than a Type C initially under consideration.

[Caryn Peterson, EVP of Regulatory Affairs at Gossamer Bio]

A Type B meeting is a formal pre-submission interaction with FDA, where we provide an overview of the NDA in the form of a briefing book that FDA will provide written responses within a defined timeline and formal meeting minutes. We submitted the meeting request in April 2026, an in-person meeting has been granted by FDA and will be held in mid-June. Based on that timing, our NDA submission target remains in September this year, subject to the outcome of the pre-NDA meeting. If that process proceeds as expected, a potential approval could follow in the third quarter of 2027.

[Caryn Peterson, EVP of Regulatory Affairs at Gossamer Bio]

To summarize, we believe PROSERA provides one adequate and well-controlled study. TORREY provides the confirmatory evidence, the seriousness of the disease, the unmet medical need, and the novel mechanism of action all support this NDA pathway. The Type B meeting is an important step in that process and supports our current NDA timing of September 2026. With that regulatory context in mind, I'll hand it over to Dr. Rob Roscigno to discuss the CT-FRI sub-study findings. Rob?

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

Thank you, Caryn. I will now spend the next few minutes walking through the PROSERA CT-FRI sub-study and what it adds to our understanding of seralutinib's effect in PAH. Let's focus on what CT-FRI adds to the PROSERA story. Clinical endpoints can tell us whether patients improved. CT-FRI helps us to understand the anatomical basis for that improvement. These analyses were performed with Fluidda's functional respiratory imaging or FRI platform, which allows us to quantify anatomical changes in the pulmonary vasculature and surrounding lung parenchyma.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

That is especially important for seralutinib because it is not simply a vasodilator. Its mechanism is designed to address remodeling biology in the lung. In TORREY, the FRI sub-study gave us an early hint that seralutinib could drive arterial reverse remodeling. The PROSERA sub-study was designed to go much deeper. It was a much larger, pre-specified exploratory sub-study designed to test whether the TORREY signal held up at scale and whether the effect extended beyond the arterial compartment.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

I want to acknowledge that this is the largest and most comprehensive CT-FRI data set ever generated from a controlled therapeutic trial in pulmonary hypertension. A total of 162 patients enrolled in the sub-study and 125 patients had paired baseline and week 24 CT scans available for analysis. These effects were observed on top of highly intensive background therapy, including patients receiving double, triple, and quadruple PAH therapy. The sub-study was balanced across arms and representative of the broader PROSERA intent to treat or ITT population on demographics, hemodynamics, and risk profile.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

The clinical endpoints in the sub-study were also consistent with the broader ITT population, including improvement in 6 minute walk distance, NT-proBNP, and REVEAL Lite 2. I'll walk you through what we found and why we think it matters. This slide gives the high-level result. seralutinib showed statistically significant treatment effects across arterial, venous, and fibrosis-like parenchymal parameters. The CT-FRI signal was not confined to one vascular compartment. The breadth and internal consistency of these effects go beyond the arterial-specific signal we first saw on TORREY.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

Importantly, the imaging parameters correlated more tightly with clinical endpoints in PROSERA, including 6-minute walk distance, NT-proBNP, and REVEAL Lite 2. The overall pattern is biologically coherent and consistent with seralutinib's inhibition of PDGFR, CSF1R, and c-KIT. In other words, the findings form a coherent anatomical pattern that maps back to seralutinib's mechanism of action. I want to point out the patient image on the right side of this slide is illustrative, but it gives a first visual sense of what we mean by reverse remodeling. At a high level, you want to see more red appear than blue.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

We'll come back to this case a little later and go through it in more detail. Let's first discuss the pulmonary vasculature. To interpret the CT-FRI findings, it helps to start with the biology. PAH affects an integrated vascular and parenchymal system. PAH has historically been treated as an arterial disease, but it is not only an arterial disease. The pathology involves arteries, the capillary bed, venous filling, inflammation, and parenchymal remodeling around the vascular bed. Those compartments are connected.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

If the arteries are obstructed, the capillaries are underperfused, transpulmonary flow is reduced, and the veins become underfilled. Inflammation and fibrosis add to the problem throughout the system. If a therapy is truly modifying disease biology upstream, you would expect downstream effects to move in a coherent direction as well. If you look at the right-hand side of this slide, you can see each pulmonary vascular compartment, its structure and function, how it is affected by disease, in addition to calling out what CT can actually detect.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

This next slide maps each target of seralutinib, PDGFR, CSF1R, c-Kit, and its antiproliferative, anti-inflammatory, and anti-fibrotic effects to each compartment of the pulmonary vasculature where we would expect it to act and to the imaging signal we observed. Starting in the pulmonary arteries, PDGFR inhibition maps to the arterial reverse remodeling signal, including reduced large arterial blood volume proportion. Next, in the parenchyma, PDGFR, CSF1R, and c-Kit inhibition map to reduced fibrosis-like parenchymal features.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

The parenchymal signal is important because it points to potential anti-fibrotic effects beyond vasodilatation. Finally, in the veins, we see increased venous volume and branching, which we view as an integrated downstream readout of improved upstream arterial parenchymal and capillary bed biology. The key point is that each compartment moves in a direction that is consistent with seralutinib's mechanism of action. With that, I'll walk through each compartment individually. PROSERA reproduced and extended the reverse remodeling signal we first saw in the TORREY study.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

In the figure on the right, seralutinib significantly reduced BV10A percentage, which measures large arterial blood volume as a proportion of total blood volume. That is consistent with proximal arterial decompression and blood volume redistribution away from larger, remodeled proximal vessels towards smaller peripheral arteries. This is the compartment where we would expect PDGFR inhibition to show up most clearly.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

BV10A percentage also demonstrated among the strongest clinical correlations of any FRI parameter. Towards the bottom of the slide, we show these clinical correlations. Importantly, changes in this arterial parameter correlated with improvements in 6-minute walk distance, NT-proBNP, REVEAL Lite 2, and ESC/ERS risk. This arterial signal is not only statistically significant, it is also clinically connected and consistent with the signal we first observed in the TORREY sub-study. Next, we look at the parenchymal signal.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

This may be one of the more important new findings in this data set. In the figure on the right, seralutinib significantly reduced fibrosis like parenchymal volume and also normalized fibrosis like parenchymal volume while placebo progressed. To our knowledge, this is the first demonstration of a statistically significant reduction in fibrosis like parenchymal features in a controlled PAH trial. These measures are CT-derived imaging metrics.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

They are not histology, but they quantify voxel-level features characteristic of fibrotic tissue using a deep learning algorithm trained on confirmed IPF patient data sets, analogous to high attenuation area or HAA approaches reported by Insmed. The reductions were consistent across subgroups, including non-CTD patients, which supports a broader anti-inflammatory and anti-fibrotic effect rather than a CTD-specific phenomenon. This signal is consistent with seralutinib's PDGFR, CSF1R, and c-KIT biology and supports a potential effect on inflammatory and fibrotic remodeling distinct from vasodilatation.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

Clinical correlations are noted at the bottom of the slide. One important point is that CT likely underestimates the full remodeling burden in PAH because much of this relevant perivascular and capillary bed biology occurs below the resolution of the CT. The detectable reduction in fibrosis like parenchymal features may capture only part of the total remodeling effect. The same fibrotic and inflammatory pathobiology is also relevant to PHILD and other fibrotic lung diseases, which supports the potential relevance of seralutinib beyond PAH.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

The venous compartment then gives us an integrated view of how these upstream effects may translate into improved blood flow. Let's look at seralutinib's effects on the pulmonary veins. In the figure on the right, seralutinib significantly increased total venous blood volume while placebo decreased. Clinical correlations are noted on the bottom of the slide. We also saw consistent increases across venous vessel sizes and vascular branching, including fractal dimension. To our knowledge, this is the first demonstration of venous vascular recovery in a controlled PAH trial.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

Why does that matter? In PAH, venous underfilling reflects reduced transpulmonary flow. It is not primarily a venous disease. If upstream arterial obstruction, parenchymal remodeling, and capillary bed impairment begin to improve, the downstream consequence should be improved venous filling. This is why we view the venous signal as more than another isolated parameter. It may be an integrated readout of the broader treatment effect upstream. The increase in venous branching is also important because it suggests improved vascular complexity, not simply passive volume redistribution.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

The next question is whether these anatomical changes relate to clinical trajectory. In the PROSERA sub-study, the correlations support that connection. The tables at the bottom of this slide show at baseline arterial, venous, and vascular complexity parameters correlated with hemodynamic and clinical measures, including pulmonary vascular resistance, mean pulmonary arterial pressure, cardiac output, NT-proBNP, and risk scores. Changes in FRI parameters also correlated with improvements in 6-minute walk distance, NT-proBNP, and risk scores.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

These relationships were not detectable in the smaller TORREY sub-study. In PROSERA, the larger sample size and updated algorithm allowed us to see a stronger link between anatomical imaging findings and clinical outcomes. That gives us confidence that these are not just imaging observations. They are biologically and clinically relevant measures that help connect structural remodeling to clinical benefit. This table pulls the compartment-level findings together all in one place.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

In the arterial category, BV10A percentage decreased consistent with reduced large artery blood volume proportion and proximal decompression. In the parenchymal category, both fibrosis-like parenchymal volume and normalized fibrosis-like parenchymal volume decreased. In the venous category, total venous blood volume, small venous blood volume, mid-sized venous blood volume, and venous fractal dimension all increased. The key point here is not any single parameter in isolation. It's the consistency of the signal across arterial, parenchymal, and venous measures.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

This pattern is what we would expect from seralutinib's mechanism, arterial reverse remodeling, reduced fibrosis-like parenchymal features, and improved downstream venous filling and vascular branching. More broadly, the pattern is directionally supportive across the data set, including parameters that did not individually reach statistical significance. Again, I wanna remind you this was a pre-specified exploratory sub-study. The p-values are nominal and unadjusted for multiplicity. To make the concept more tangible, this slide shows two patient examples.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

These are individual patients, not the trial result, and they are not representative of the full study population. Both patients were on triple stable background therapy and were functional class 3 at baseline. In the placebo case on the left, the patient remained on intensive background therapy, but the vasculature worsened over time. Total venous volume decreased, proximal arterial volume increased, and 6-minute walk distance stayed essentially flat. Let's compare this to the seralutinib case on the right. I showed this image to you earlier.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

Here we see the visual pattern we mean by reverse remodeling. Large arterial volume decreased, small arterial volume increased, total venous volume increased, 6-minute walk distance improved, and NT-proBNP declined. The important point is that the visual pattern lines up with the population-level data, arterial decompression, venous filling, and clinical improvement all moving together. This next example focuses specifically on the fibrosis-like parenchymal signal.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

The images on the left are from a single seralutinib-treated patient on double background therapy who had a visible reduction in fibrosis-like CT features from baseline to week 24. The patient also had improvement in 6-minute walk distance and NT-proBNP. The important point is not the individual patient alone. It is that the visual change is directionally consistent with the broader parenchymal treatment effects seen in the sub-study. Fibrosis volume was quantified using FibroNet, a deep learning algorithm trained on confirmed IPF patient data and analogous to high attenuation area, or HAA, approaches used in ILD imaging.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

Again, CT only detects changes above a certain resolution. It likely understates the full burden of remodeling, particularly around the capillary bed. This supports the potential relevance of seralutinib in diseases where vascular remodeling, inflammation, and fibrosis overlap, including PHILD and other fibrotic lung diseases. To summarize, if we step back, PAH is a multi-compartment disease, and seralutinib appears to affect these compartments in a coherent way, even on top of intensive background therapy.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

The importance of these data is the consistency of the signal across anatomy, mechanism, and clinical outcomes. Multi-compartment vascular remodeling effects of this breadth have not been shown by traditional vasodilator therapies, which suggest added structural benefit rather than something redundant with existing vasodilator therapy. The arterial remodeling signal we first saw in the TORREY sub-study is now reproduced and extended in a much larger phase III sub-study.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

In the parenchyma, seralutinib reduced fibrosis-like features supporting potential anti-fibrotic activity that is distinct from vasodilatation. In the vein, seralutinib showed what we believe is the first controlled trial evidence of venous vascular recovery, including gains in venous blood volume and branching. Taken together, these imaging signals point to a mechanism-based effect on disease biology consistent with PDGFR, CSF1R, and c-KIT pathway inhibition. The clinical correlations are also important.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

These structural imaging findings correlated with improvements in 6-minute walk distance, NT-proBNP, and REVEAL Lite 2. That links anatomical remodeling to clinical benefit. These data strengthen the cumulative weight of evidence for seralutinib across the program, including the placebo-controlled phase I-B, the Phase II TORREY study, and the Phase III PROSERA study. Taken together, we believe the CT-FRI data provide important anatomical support for the clinical benefit observed in PROSERA and reinforce seralutinib's differentiated profile in PAH.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

With that, I'll turn the call back over to Bryan to discuss our financial position and recent capital structure actions.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Thanks, Rob. As of March 31st, 2026, we had cash and cash equivalents and marketable securities of $99 million. Based on our current plans, we expect our cash runway to extend into the 1st quarter of 2027. Operating expenses will come down now that the PROSERA study has wound down. Additionally, we have implemented a reduction in force and broader cost containment measures. To this end, the 1st quarter included one-time charges, and our go-forward quarterly burn should be lower. I will leave the detailed financials to the press release and our 10-Q filing that we did on Friday afternoon.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Moving on to the bond exchange. We have $200 million of aggregate principal amount convertible senior notes approaching maturity in 2027. With that maturity coming closer, addressing the capital structure proactively was a necessary step to keep the company focused on NDA execution and potential commercialization. We've been working constructively with our note holders since the PROSERA top-line readout in February. Both sides recognize the value of aligning the capital structure with the path forward as soon as practical.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

We were able to come to terms efficiently. We view the outcome as an important step in removing the overhang and improving our focus on execution. Under the exchange, for each $1,000 of existing notes tendered, holders will receive a combination of equity consideration, new secured convertible notes, and for those who tender early, warrants. The new notes are secured by a priority, first priority lien on substantially all the company's assets and bear cash interest at 7.5% paid semi-annually.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

On a fully subscribed basis, this takes our outstanding convertible debt from $200 million down to $72 million, a reduction of $128 million, and extends our debt maturity from 2027 to 2030. The exchange requires a minimum participation of 98%, which may be waived. We are also running a concurrent consent solicitation to remove substantially all restricted covenants from the existing indenture. Cantor Fitzgerald is serving as dealer manager, and Latham & Watkins is serving as our legal counsel.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Additional details are included in the press release, and our Form 8-K that was filed with the SEC this morning. With that, let me turn it back over to Faheem for some closing remarks.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Thanks, Bryan. Stepping back, the key point today is that our conviction has strengthened. We've taken the balance sheet actions needed to align the company with a path forward. We now have a confirmed Type B pre-NDA meeting and expect to submit the NDA in September of 2026. We also have CT-FRI data showing multi-compartment reverse remodeling across arterial, venous, fibrosis-like, and complexity parameters with clinical correlations that support the biological relevance of those findings.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Taken together with the phase III PROSERA data and the phase II TORREY data, we believe the overall evidence supports an NDA path for seralutinib. With that, operator, we're ready to open the line for questions.

[Operator]

As a reminder, to ask a question, simply press star one on your telephone keypad. Again, that's star one to ask a question. Our first question comes from the line of Yasmeen Rahimi with Piper Sandler. Please go ahead.

[Analyst at Piper Sandler]

Hi, this is Dominic on for Yasmeen Rahimi. Congrats on all the great updates in the PROSERA CT-FRI data. Could you help us understand how this data not only helps for the upcoming pre-NDA Type B meeting, but also potentially support a differentiated label? Kind of what are your thoughts on that and the plan with those data? Thank you.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Yeah. Caryn, we'll ask you to take that first part of that question.

[Caryn Peterson, EVP of Regulatory Affairs at Gossamer Bio]

Sure. Thank you, Faheem. The data that was presented today is going to go into the NDA. We did not get it in time to put it into the pre-NDA briefing package, although we will highlight it at the meeting. We believe it's gonna be very important in terms of confirmatory evidence as we look at the biology and mechanistic plausibility. The dataset, once fully complete, will be a big part of the NDA, and if we do get it in the label, it'll be in the pharmacodynamic section of the label. Those discussions will occur at the meeting in June.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Bob Smith.

[Caryn Peterson, EVP of Regulatory Affairs at Gossamer Bio]

Thank you.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Can you handle the last part, the question around differentiation?

[Bob Smith, Chief Commercial Officer at Gossamer Bio]

Sure. Absolutely. We feel like, first of all, the profile of seralutinib, between the data in phase I and phase II is extremely strong. I think it even gets stronger with our phase III data. With the FRI imaging data, this is unprecedented in the market. To my knowledge, we have not seen any other PAH therapy have this sort of information to clearly, in humans, show a strong reverse remodeling capability. So we expect the label to be highly differentiated because of this.

[Analyst at Piper Sandler]

Great. Thank you so much.

[Operator]

Your next question comes from the line of Joseph Schwartz with Leerink Partners. Please go ahead.

[Heidi Jacobson, Analyst at Leerink Partners]

Hi, this is Heidi on for Joe. Thanks so much for taking our question. Can you walk us through the timeline between now and a potential September filing? What steps are getting to a potential NDA filing in addition to the Type B meeting? Thank you.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Caryn?

[Caryn Peterson, EVP of Regulatory Affairs at Gossamer Bio]

Yeah, sure. We're actively working on the NDA submission as we speak. Obviously, it's a very large dossier and all of the analyses are ongoing and will be completed, you know, late August so that we can get the filing in mid-September. Everything is happening in parallel to the meeting, and we have been planning this for quite some time, so we're on track, and we'll be ready to file in September.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

It's Bryan. I would just add the following, that the decision to go from a Type C to a Type B meeting, again, not only was on the basis of the totality of the evidence that we've seen through all of the clinical work with seralutinib, but at the recommendation of a number of our FDA advisors and consultancies that we've been using. That upon their review of the data as well as the competitive landscape, suggest that we should move aggressively forward because of the high unmet medical need.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Again, I think it's very important that you take into consideration that it's not just Gossamer making this decision, but really robust support from those who have walked the walk, if you will, with the FDA within cardiorenal for many years.

[Heidi Jacobson, Analyst at Leerink Partners]

Great. Thanks so much.

[Operator]

Your next question comes from the line of Eliana Merle with Barclays. Please go ahead.

[Analyst at Barclays]

Hi, this is Jasmine on for Olivia Brayer. Thank you for taking our questions, and congratulations on the data. Trying to understand the clinical relevance of these CT-FRI measures, is it common for physicians to do imaging like this when they manage these PAH patients to measure progression or when diagnosing? Secondly, would you expect the imaging results to deepen over time, and will patients in the sub-study have more imaging done at a later time point? Thanks.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Jean-Marie?

[Jean-Marie Bruey, SVP of Translational Medicine and Research at Gossamer Bio]

To answer the question, I think when we look at the standard endpoint, the PVR, the 6-minute walk, the NT-proBNP, they measure the functional hemodynamic consequence of disease, but you don't visualize underlying structural change. The clinical endpoint can be affected by placebo or background therapy. What we have, the data we have with FRI, it provides a mechanistic insight. It separately quantifies arterial, venous, and fibrotic-like feature and vascular complexity change. We're trying to directly tie those markers with the disease pathology.

[Jean-Marie Bruey, SVP of Translational Medicine and Research at Gossamer Bio]

I think the value is biological plausibility. FRI strengthen understanding of how seralutinib works. We have a structural reverse remodeling versus acute vasodilation. It's not a surrogate endpoint, I wanna make sure of that, but it adds mechanistic credibility to support totality of evidence for regulatory and clinician. Concerning the questions at 48 weeks or 72 weeks, we don't have the data yet. We will look into it.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Just to be clear, this technology is not something that's standard in the context of physician and clinical practice. As what Jean-Marie said, it really does bring the mechanistic evidence and the structural evidence to the table as to what seralutinib is doing in the context of the lungs. We will certainly be looking at the possibility of repeating some of this imaging at later time points. Obviously, when we have that data, we'll present it back to you.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

I think to add to what Faheem said, what's most important here is no other sponsor has ever done this robust level of analysis using CT. We do think that what Gossamer has achieved with this Fluidda CT study is going to set a new standard for how the community will look at a pharmaceutical intervention in PAH. To see, as Rob laid out, all three compartments having a statistically significant effect, we think is not only very beneficial for patients but is certainly setting a new standard for drugs in pulmonary arterial hypertension.

[Analyst at Barclays]

Great. Thanks so much.

[Operator]

Your next question comes from the line of Vamil Divan with Guggenheim Securities. Please go ahead.

[Vamil Divan, Analyst at Guggenheim Securities]

Great. Thanks for taking my questions. Maybe two, if I could. One, just curious in terms of communication post the meeting with the FDA. We assume to hear back sort of once you get the minutes, I don't know, I guess maybe in the July sort of timeframe or next updates we'd get from the company there. My other question is sort of tied to one of the earlier questions and just sort of based on the results here, I guess there's a couple parts to the question. One, you mentioned that these patients in general seem to do similar to the patients in the broader study population of the clinical endpoint.

[Vamil Divan, Analyst at Guggenheim Securities]

Maybe you can provide a little bit more detail on that just in terms of the PVR 6-minute walk, you know, results you've seen with these patients. I'm sort of curious what this means in terms of how you think about commercialization. Like, are there certain patient types or, you know, patient severities that you think may be better candidates for seralutinib than others based on the competitive dynamics out there, the other options that doctors have available? Thanks.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Yeah, thanks for your question. Rob, you wanna take the Yeah, first piece.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Yeah. Vamil, we'll provide an update on our FDA disclosures during our second quarter results that we'll do later in the summer after the meeting. Faheem, I'll let you direct the more important question for Vamil.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Yeah. Rob, you wanna handle it? Second piece.

[Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease at Gossamer Bio]

The second question, I believe, was how these patients, if you will, perform regarding their clinical endpoints as compared to the overall PROSERA intent to treat population. These patients did show significant improvement in 6-minute walk and significant lowering or decrease in NT-proBNP, exactly what we would expect and very, if you will, supportive of this cohort. As far as your second question.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Yeah. Well, the I think the last part of your question was about commercial utilization and how would seralutinib get used in a commercial context. Bob, you can add in, but basically, clearly you can see a very pronounced effect in the intermediate to high-risk subgroup. That's pretty clear. The story doesn't end there. When you see the CT-FRI data, you realize that something profound is going on in the context of the lung, and even through the TORREY data, the echo data showing us what's going on in the right heart, that kind of so-called reverse remodeling context.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

I would just like to tell you that the clinical community is quite intrigued about using this drug across the spectrum of patients because even in the lower risk patients, the patients that are otherwise functionally quite capable, there is the potential to be able to use this drug earlier to prevent longer term progression and, given the safety profile of the drug, not impact quality of life, and that quality of life component becomes very important as you're using it in a patient that has otherwise pretty good functional capabilities. We do see the potential for seralutinib to be used across the spectrum of PAH patients.

[Bob Smith, Chief Commercial Officer at Gossamer Bio]

Yeah. Faheem, that's exactly what I was gonna say. I would just say with this data, I think it will motivate the market to start patients sooner on seralutinib, and as Faheem said, because of what we're seeing from a safety and tolerability standpoint and efficacy standpoint now as imaging data, that they'll be able to stay on for a much longer time, with that hopefully portending, you know, better outcomes for these patients.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Yeah. I don't think we can stress enough how important a new mechanism is for these patients, and especially a new mechanism that doesn't carry the significant burden of toxicities that many of the current therapies do.

[Vamil Divan, Analyst at Guggenheim Securities]

Okay. Thank you. Congrats on all the progress.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Thank you.

[Bryan Giraudo, COO and CFO at Gossamer Bio]

Thanks, Vamil.

[Operator]

With no further questions in queue, I will now hand the call back over to Faheem Hasnain, CEO, for closing remarks.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

Yeah. Thank you very much, thanks all for listening in to the call. I just wanna end this call by first off thanking the patients that participated in the PROSERA study. Obviously, without that participation, you know, we're not able to advance treatments here for PAH. I'd also like to thank the patient advocacy groups that have been very supportive of Gossamer and the opportunity that seralutinib represents to their patients.

[Faheem Hasnain, Founder, CEO, and Chairman at Gossamer Bio]

I wanna thank the investigators and more broadly the clinical community where we have been experiencing, I'm here at ATS now as we speak in Orlando, just the tremendous amount of support that we're getting and encouragement, and quite frankly the expectation that we will continue to push forward and get this drug approved. Thank you everybody and we look forward to further updates. Thank you.

[Operator]

Thank you again. Thank you again for joining us today. This does conclude today's conference call. You may now disconnect.

Participants

Executives

• Bob Smith, Chief Commercial Officer
• Bryan Giraudo, COO and CFO
• Caryn Peterson, EVP of Regulatory Affairs
• Faheem Hasnain, Founder, CEO, and Chairman
• Jean-Marie Bruey, SVP of Translational Medicine and Research
• Rob Roscigno, SVP of Clinical Development-Pulmonary Vascular Disease

Analysts

• Heidi Jacobson, Analyst at Leerink Partners
• Vamil Divan, Analyst at Guggenheim Securities
• Analyst at Barclays
• Analyst at Piper Sandler